<?php
/************************************************************************
 * This file is part of EspoCRM.
 *
 * EspoCRM - Open Source CRM application.
 * Copyright (C) 2014-2021 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
 * Website: https://www.espocrm.com
 *
 * EspoCRM is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * EspoCRM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU General Public License version 3.
 *
 * In accordance with Section 7(b) of the GNU General Public License version 3,
 * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
 ************************************************************************/

namespace Espo\Core\FileStorage;

use Espo\Core\InjectableFactory;

use Espo\Entities\Attachment;

use Espo\Core\Exceptions\Error;

/**
 * An access point for file storing and fetching. Files are represented as Attachment entities.
 */
class Manager
{
    private $implementations = [];

    private $implementationClassNameMap = [];

    private $injectableFactory;

    public function __construct(array $implementationClassNameMap, InjectableFactory $injectableFactory)
    {
        $this->implementationClassNameMap = $implementationClassNameMap;
        $this->injectableFactory = $injectableFactory;
    }

    private function getImplementation(?string $storage = null)
    {
        if (!$storage) {
            $storage = 'EspoUploadDir';
        }

        if (!array_key_exists($storage, $this->implementations)) {
            if (!array_key_exists($storage, $this->implementationClassNameMap)) {
                throw new Error("FileStorageManager: Unknown storage '{$storage}'");
            }
            $className = $this->implementationClassNameMap[$storage];
            $this->implementations[$storage] = $this->injectableFactory->create($className);
        }

        return $this->implementations[$storage];
    }

    /**
     * Whether a file exists in a storage.
     */
    public function isFile(Attachment $attachment) : bool
    {
        $implementation = $this->getImplementation($attachment->get('storage'));
        return $implementation->isFile($attachment);
    }

    /**
     * Get file contents.
     */
    public function getContents(Attachment $attachment) : ?string
    {
        $implementation = $this->getImplementation($attachment->get('storage'));
        return $implementation->getContents($attachment);
    }

    /**
     * Store file contents.
     */
    public function putContents(Attachment $attachment, string $contents)
    {
        $implementation = $this->getImplementation($attachment->get('storage'));
        $implementation->putContents($attachment, $contents);
    }

    /**
     * Remove a file.
     */
    public function unlink(Attachment $attachment)
    {
        $implementation = $this->getImplementation($attachment->get('storage'));
        $implementation->unlink($attachment);
    }

    /**
     * Get a file path.
     */
    public function getLocalFilePath(Attachment $attachment) : string
    {
        $implementation = $this->getImplementation($attachment->get('storage'));
        return $implementation->getLocalFilePath($attachment);
    }

    /**
     * Whether a file can be downloaded by URL.
     */
    public function hasDownloadUrl(Attachment $attachment) : bool
    {
        $implementation = $this->getImplementation($attachment->get('storage'));
        return $implementation->hasDownloadUrl($attachment);
    }

    /**
     * Get download URL.
     */
    public function getDownloadUrl(Attachment $attachment) : string
    {
        $implementation = $this->getImplementation($attachment->get('storage'));
        return $implementation->getDownloadUrl($attachment);
    }
}